1. Field of the Invention
The invention relates to oil well technology. More particularly, the invention relates to a downhole fluid flow and pressure equalization control and choke devices.
2. Prior Art
Flow control has been a concern of the oil drilling industry since the first well produced a gusher like that of spindle top in Texas on Jan. 10, 1901. Initially, flow control was focused upon surface based apparati, however, as technology advanced and multiple production zone/multiple production fluid wells grew in popularity, flow control downhole has become increasingly important.
One particular prior art device which has been very effective is the CM sliding sleeve commercially available from Baker Oil Tools, 6023 Navigation Boulevard, Houston, Tex. 77011. The sleeve employs one outer housing with slots and one inner housing with slots. The slots are alignable and misalignable with axial movement of the inner housing relative to the outer housing. The tool is effective for its intended purpose but does not provide any selectivity regarding where on the circumference flow is desired. Other valving and choking devices are also available in the prior art but there is still a need for more efficient devices and specific devices to function where others have not proved effective. Moreover, devices which function with less or no input from the surface are also likely to have a significant positive impact on the industry.